Hexy covers

Hexagon patterns on a manhole cover usually indicate that it is for a telecom or telephone utility.  Here are two:

 

 

Bell in hex

This cover features the bell symbol of a telephone company and various design elements - mostly hexagons - in circles of 12.

 

 

Six hexagon holes

This manhole cover features an outside ring of 12 "teeth" and six "erupting" hexagons, six free floating hexagons, six hexagons with aeration holes, and one central hexagon.

Both of these were seen in the street beneath our feet.